TB patients and household contacts were recruited in a longitudinal study, conducted at Gulab Devi Chest Hospital, Lahore, Pakistan in 2009/2010. Detailed characteristics of subjects, treatment regimen/outcome and recruitment procedures can be found in Table 1 and have been described previously [20 (link)]. The TB patients (n = 26) were recruited prior to starting TB treatment and after two months intensive phase treatment according to the National Tuberculosis Program guidelines (2HRZE). It was only possible to follow up a subset of those patients studied pre-treatment at two months due to early discharge of patients from the hospital. Household contact was defined as living in the same room when the TB patient was diagnosed. QuantiFERON-TB Gold (Cellestis, Ltd, Carnegie, Australia) was used in conjunction with lack of clinical symptoms or radiological evidence of TB to categorise the healthy household contacts as latently infected or not infected with M. tuberculosis.
Three ml venous blood from each patient or contact was collected into Tempus RNA tubes (Applied Biosystems) and stabilised by shaking vigorously for 10 seconds prior to freezing at -80°C.
Three ml venous blood from each patient or contact was collected into Tempus RNA tubes (Applied Biosystems) and stabilised by shaking vigorously for 10 seconds prior to freezing at -80°C.
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